A number of different photovoltaic devices have been developed for producing electrical power both for both terrestrial and space applications. Space craft have a need for high levels of reliable electrical power over very long periods. For space applications, the photovoltaic device must be highly efficient, light in weight, sufficiently sturdy to withstand launch forces and resistant to degradation from the space environment of proton and electron impact and electrostatic effects.
Most photovoltaic apparatus presently used with space vehicles utilize large planar photovoltaic cell arrays that extend from sides of a support structure. These arrays are generally folded for launch, then are unfolded for deployment in space. They tend to be undesirably heavy and to require complex deployment arrangements. The many photovoltaic cells that make up the arrays are expensive and fully exposed to degradation from radiation, particles, etc. Electrically conductive circuitry associated with those cells is also exposed to the ambient space environment, providing opportunities for disadvantageous charge buildup, discharge and leakage currents.
Photovoltaic panels have been developed using strip reflectors of different types. Typical such panels include a plurality of spaced strip reflectors to reflect sunlight to photovoltaic cells. While quite effective, these prior panels lack the desired high regidity, efficiency and resistance to electrons, protons, electrostatic effects, etc.
Therefore, there is a continuing need for large photovoltaic panels for use in space applications that have higher efficiency, maximize the number and total area of photovoltaic cells per watt of electrical output greater rigidity over a large panel and that provide greater protection for the photovoltaic cells from degradation due to electromagnetic and particle irradiation and electrostatic effects.